Feed-controlling means for rock drills



March 9 ,1926. w. G. NAISMITH FBBD co'NTnoLLINe MEANS Fon Rock DRILLs Filed July 1, 1920 Patented Mar. 9, 1926.

UNITED Srrss ,.PATENT OFFICE..

WILLIAM Gr. NAISMITI-I, OFDENVER, COLORADO, ASSIGNOR TO THE `DENVER ROCK DRILL MANUFACTURING` COMPANY, OF DENVER, COLORADO, CORPORATION OF DELAWARE.

Application med my 1,

To 'all fwwm it may concern: Be it kknown that l, WiLiirAM G. Nar- SMITH, a subject of the King ofv Great lBritain, V:residing at Denver, in ythe county of vDenver and `tate of Colorado, have invented certain new and useful Improvements in Feed-Controlling lVleans for Rock Drills, vof which the following is a specification.

` The present invention relates to feed regulating means for rock drills andsimilar tools in which the means for holding the tool to its work and advancing it is effected'by fluid under pressure.

One of the primary objects is to provide a simple and effective means whereby the action of the feeding means can be controlled and is automatically governed to prevent its quick operation in case the normal resistance to its movement is suddenly or unexpectedly relieved.

An embodiment of the invention is illustrated in the accompanying drawings, wherein Figure 1 is a vertical sectional view through a portion of a rock drilling apparatus showing the novel feeding means,

Figures 2 and 8 are sectional views respectively on the lines 2-2 and 3-3 of Figure 1. u

Figure 4 is a detail sectional view on line 4-4 of Fig. 1 showing the relief port that may be employed for releasing the air Vunder pressure from the reservoir. t

In the embodiment disclosed, a portion of a tool-actuating motor is shown at 4, and may be of any well known or desired construction, said motor having a rear head block 5 provided with a nipple 6 to which may be connected the usualhose line for air or other gaseous fluid under pressure.

Mounted on the rear end of the nead block 5 is a cylinder member, comprising a barrel 7 and having a head 8 at its inner end that is interposed between the said barrel 7 and the head block 5. Operating in the barrel 7 is the usual piston 9 having a rod 1() that -slidably projects through the outer end of the barrel 7 and is provided with a supportengaging spur 11. y

Surrounding the upper or inner portion of the barrel 7 is a reservoir 12 for liquid, preferably oil, said reservoir having a filling opening 13 that may be closed by a removable plug 14. Extending from the bottom FEED-CONTROLLNG MEANS FOR ROCK DRILLS.

1920. Serial No. 393,373.

of the reservoir, is a conduit 15 that passes through the head 8, and has aport 16 opening into the upper end of the barrel'7 above the piston 9. In the head 8 and around the conduit 15 is formed a valve seat 17, adapted to cooperate with which-is a plungervalve 18 having an actuating stem 19 projecting from the head. A spring 20 within the head 8 bears against the inner end of the valveV 18 and normally holds the same open. From the supply nipple 6 in the headblock 5a passageway 21 leads tothe tool-actuating motor 4, and another passageway 22'l'eads from said nipple to the upper end of the reservoir 12. The passageways 21 and 22 are controlled by a throttle valve 23 having ports 24 and 25 respectively movable into communication with said passageways 21 and 22. y

Vith the parts as shown in Figure 1, it will be evident that gaseous motive fluid is being delivered to the drill-actuating motor for operating it, and that fluid is also passing through the conduit 22 into the reservoir, thus placing the liquid in said reservoir under pressure and causing rit to pass through the conduit 15 into the upper end of the barrel 7, where it acts against the piston 9 to cause the extension of the feeding means in a manner readily understood. The conduit 15 being relatively small the amount of liquid passing therethrough is restricted, so that if the tool should break or the machine become displaced, the extension of the feeding means will be relatively slow. The operator moreover can at any time slow down' the feed by operating the valve 18 by means of the projecting stem 19, or he may stop the feed entirely by 'completely closing the Yvalve. When the fluid is cut olf by turning the valve 23, then the port 22 is in communication with an exhaust port 26 by a channel 27 in the valve 23 as shown in Figure 4, whereupon the air or other fluid in the top of the reservoir 12 can escape and the weight of the motor and cylinder member will cause the same to descend to the position shown in Figure l.

From the foregoing, it is thought that the construction, operation a'nd many advantages of-the herein described invention will be apparent to those skilled in the ait. without further description, and it will be understood that various changes in the size, shape, proportion and minor details of construction, may be resorted tol without departing from the spirit or sacrificing any of the advantages of the invention.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is

l. The combination with a tool-actuating motor, of Huid operated7 extensible feeding means therefor including a cylinder member at the rear end of the tool actuating motor and a piston operating in the cylinder member and having' a portion that slidably projects from its rear end, connecting means interposed between the tool-actuating motor and the cylinder member; a reservoir for liquid on the cylinder member, a liquid e-onduit between the low r part of the reservoir and the cylinder member above the piston, said conduit 'extending through said connecting means7 and valve mechanism in the connecting means controlling the passage of fluid to the tool-actuating motor and the reservoir and the passage of liquid through said conduit.

2. The combination with a tool-actuating motor, of fluid operated, extensible feeding means therefor, including a cylinder member at the rear end of the tool actuating motor and a piston operating in the cylinder member and having a portion that projects from its rear end, connecting means interposed between the tool-actuating motor and the cylinder member, a reservoir for liquid on the cylinder member a liquid conduit between the lower part of the reservoir and the upper end of the cylinderl member and extending' through vsaid connecting means, a valve in the connecting means controlling the conduit, a iiuid supply passageway having branches in the connecting means leading to the tool-actuating motor and to the reservoir, and a valve in said connecting' means controlling the branches.

In testimony whereof I affix my signature.

IVILLIAM G. NAISMITH.

slidably 

